Ann: 204 Carat Diamond Recovered at Mothae Mine, page-52

I think the company has been moving away from recording individual diamonds and more to overall revenue, which internally makes sense.
For specific, unique stones such as the Pink it offers more in terms of marketing so an update would be a good thing!
Personally I would not be too concerned about its sale, being so unique, not sure how many Intense orangey Pink 15ct diamonds exist? It has no specific value other than what a collector is willing to pay. On the low side it may be seen as US$5-6million stone with orangey pink not regarded as highly as say a purple pink or straight pink. On the high side it may be a US$9-12 milion something different for a collector.
Many of these investors don't seek the limelight and negotiations will remain quiet.
The other option is to auction the stone and try to create a buzz around it.
Waitng a couple of years for the right buyer, market conditions may prove fruitful if it ends towards the higher price range, though I agree it would be helpful to investors if a direction was given!